MP83-07 ROLE OF HINT3 IN P21 INDUCED NECROTIC CELL DEATH UPON BCG EXPOSURE IN UROTHELIAL CARCINOMA CELLS

Abstract

You have accessJournal of UrologyBladder Cancer: Basic Research & Pathophysiology IV1 Apr 2016MP83-07 ROLE OF HINT3 IN P21 INDUCED NECROTIC CELL DEATH UPON BCG EXPOSURE IN UROTHELIAL CARCINOMA CELLS Gopitkumar Shah, Fanghong Chen, GuangJian Zhang, and William See Gopitkumar ShahGopitkumar Shah More articles by this author , Fanghong ChenFanghong Chen More articles by this author , GuangJian ZhangGuangJian Zhang More articles by this author , and William SeeWilliam See More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.2189AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Exposure of urothelial carcinoma cells (UCC) to BCG results in activation of p21. Previously we have shown that p21 is sufficient and necessary for the full antiapoptotic effect of BCG. p21 expression alone is necessary for HMGB1 release which is required for direct cytotoxic effect of BCG in vivo. Microarray of p21 overexpressing cell lines showed induction of hint3 gene, however its role has not been elucidated. The objective of the current study is to characterize the role of hint3 in antiapoptotic effects of BCG. METHODS The blockade of hint3 expression in response to BCG was established in the human UC line T24 using the stable transfection of a siRNA construct targeting hint3 mRNA. The effect of inhibiting hint3 expression on tumor phenotype was assessed using assays for viability, LDH and HMGB1 release and caspase activation. RESULTS Exposure of parental UC cell lines to BCG resulted in significant increase in hint3 expression. Blockade of hint3 expression using shRNA decreased its expression by 3-5 folds in BCG exposed cells (p < 0.05). LDH and HMGB1 release in response to BCG was significantly lower in hint3 mutant cell line compared to the parental cell line and scrambled control cell lines (p < 0.01 for LDH; p < 0.05 for HMGB1). There was no significant decrease in BCG cytotoxicity as measured by decrease in viability amongst the parental and mutant cell line ( p = 0.12). Hint3 mutant cell lines showed significant increase in caspase activity in response to BCG exposure compared to parental and control cell lines p < 0.05). CONCLUSIONS BCG induces hint3 expression in p21 dependent manner. Hint3 mutation results in decreased HMGB1 release indicating the p21 acts via hint3 for induction of HMGB1 release. Hint3 mutation also induces caspase 3 activity indicating changes in mechanism of cell death from necrosis to apoptosis. As HMGB1 is critical for in vivo cytotoxicity of BCG, characterizing the pathways for HMGB1 induction would provide a novel target to improve BCG efficacy. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e1083 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Gopitkumar Shah More articles by this author Fanghong Chen More articles by this author GuangJian Zhang More articles by this author William See More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...